Path: csiph.com!newsfeed.hal-mli.net!feeder3.hal-mli.net!newsfeed.hal-mli.net!feeder1.hal-mli.net!border3.nntp.dca.giganews.com!border1.nntp.dca.giganews.com!nntp.giganews.com!news.bbs-scene.org!macgui.com!mressl From: mressl@macgui.com (Marc S Ressl) Newsgroups: comp.sys.apple2 Subject: Re: Apple IIGS bank latching Date: Tue, 6 Mar 2012 16:07:50 +0000 (UTC) Organization: Mac GUI Lines: 36 Message-ID: References: <5764e358-0a03-40dd-8e1a-845ee20f68ee@w29g2000yqw.googlegroups.com> NNTP-Posting-Host: gunshin.wiredns.net Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-Trace: technocratmedia-w1.news.bbs-scene.org 1331050070 14105 74.119.145.48 (6 Mar 2012 16:07:50 GMT) X-Complaints-To: abuse@bbs-scene.org NNTP-Posting-Date: Tue, 6 Mar 2012 16:07:50 +0000 (UTC) User-Agent: Mac GUI City Usenet Posting Xref: csiph.com comp.sys.apple2:5218 Antoine Vignau wrote: > (5) returns 02 > (6) returns 03 > (7) returns > * 1900: 19 > * 2000.2007: 12 34 00 00 00 00 00 00 > * 2080.2087: 56 78 00 00 00 00 00 00 > * 20A0.20A7: 00 00 00 00 00 00 00 00 > * 9D00: 9D > * 9E00: 9E > * 9F00: 9F > * A000: A0 > > Antoine > Hello Antoine. Now this is most interesting! :-). Here are the findings: * The Apple IIe memory switches are always active for bank $E0. * If the language card and I/O is enabled, Apple IIe memory switches are active for bank $00. * If shadowing is enabled for all banks, memory switches are active for all even banks ($00, $02, etc). * ROM is always available when the language card is enabled (Sweet16 1, KEGS 0 :-) ) * The New Video "memory linearization" appears to not scramble the contents of video memory (I'm still having a hard time understanding this, as I believed it would). I hope this information is useful to authors of Apple IIGS emulators :-). With the best wishes, Mar.c-